Generally, oil heavy fractions contain paraffins and asphaltenes that tend to crystallize under cooling and/or a change in operation conditions in oil fractions which contain them. A drawback of the presence of paraffins and asphaltenes in oil fractions is that they sediment in pipings, thereby clogging the hydrocarbon production flow. These sediments have to be removed from the production lines, containers and equipment employed in oil production in order to maintain process efficiency.
To this end, sulfur trioxide is usually employed to form a dispersible material with the paraffin and to remove it with an aqueous liquid and a surfactant. Solvents and dispersing agents such as a primary alcohol and ethylene oxide co-polymers with sodium silicate and succinamide N-substituted ethers may also be used. Likewise, several compositions aimed to achieve this object have been developed.
For example, U.S. Pat. No. 6,090,769 relates to asphalt and heavy oils degreaser comprising a cyclic hydrocarbon solvent, dipropylene glycol mono n-butyl ether, a volatility stabilizer, an aromatic alkyl sulfonic acid salt, a branched ethoxylated alcohol and ethoxylated alkyl mercaptane. Said degreaser has suitable solvent and detergent properties. To that end, the volatility stabilizer synergically acts with the cyclic hydrocarbon solvent and dipropylene glycol mono n-butyl ether.
Document WO 2011/062799 provides a method of removing depositions from oil deposits, involving heating the sediment and/or contacting it with the reaction product from an exothermic reaction of a solvent with an acid. Nonetheless, this method has the drawback of using corrosive substances which can affect the duct materials, along with the requirement of including an additional method in the crude oil production process.
On the other hand, documents WO 2012/009128 A2 and WO 2012/129302 A2 provide compositions with nanomaterials being used as drilling fluids. The compositions have improved properties such as wettability, friction reduction, corrosion resistance and rheological properties compared to other existing fluids. These compositions modify the physical properties of asphaltene such that they prevent it from adhering to the drilling bit surfaces during the well drilling operation. The compositions described in both documents are formulated on an aqueous base or as an emulsion and further comprise nanoparticles of metal oxides, graphite or graphene. Nonetheless, these compositions have the drawback of using a laborious formulation process and being non-degradable.
In view of the above, there is a need to provide alternate compositions allowing suitable dispersing of paraffins and asphaltenes, being easy to formulate and environmentally friendly.